In sub-Saharan Africa, the burden of HIV/AIDS and malaria is disproportionately high and co-infection may be as high as 30 percent among HIV-positive populations in some African settings. Now, a new study by Harvard School of Public Health researchers and their colleagues working in Tanzania finds that HIV infection greatly increases children’s risk of developing malaria, and amplifies the frequency of the disease.

“This study captures the most up-to-date association between HIV and the development of malaria among HIV-exposed children in sub-Saharan Africa,” said lead author Amara Ezeamama, a research fellow at HSPH. “Our findings support the need for a high level of adherence to malaria prevention measures by caregivers of HIV-exposed children. In addition, such children will benefit from proactive evaluation for malaria, and timely treatment when needed, as part of their routine healthcare.”

By recruiting subjects in the community, the researchers were able to access a wider segment of Tanzanian society. They enrolled 2,387 newborn children of HIV-infected Tanzanian mothers in the study and followed them for two years at antenatal clinics in Dar es Salaam between 2004 and 2008. All babies received the drug cotrimoxazole for six months to protect against malaria infection, with children who were breastfeeding or HIV-positive continuing on the drug. All children presenting symptoms consistent with malaria were evaluated by study physicians and treated where necessary over the course of the study.

The study will appear in the May 15, 2012 edition of The Journal of Infectious Diseases. Read abstract.

The findings show that despite the use of cotrimoxazole to prevent malaria infection, and widespread breast feeding, which also has been demonstrated to be protective, HIV-positive children in the study population were 67% more likely to develop malaria than HIV-negative children. Among children who suffered at least one bout of malaria, HIV-positive children developed a second episode of malaria sooner than HIV-negative children.

One limitation of the study was that the researchers were not able to control for the use of bed nets, which protect against bites from malaria-spreading mosquitos.

The study’s findings show that HIV is a risk factor for the development of malaria. “Pro-active malaria disease prevention and treatment is needed for all children in sub-Saharan Africa, particularly those exposed to HIV in-utero in regions with substantial HIV and malaria overlap,” said Ezeamama. She and her colleagues call for future research to further evaluate the use of malaria-preventing drugs versus placebo among HIV-positive individuals using a randomized controlled trial.